[llvm] [lldb] Configure pyright to the documented minimum python version (PR #162952)

[David Spickett via llvm-commits]

DavidSpickett wrote:

I'm fine with this. It'll be unenforced, but useful for anyone who does use the tool. Since there's no enforcement upstream of this, people should note take it as an endorsement or commitment to zero errors when using it. Someone will but that's on them.

Going to add a few others to review, including lldb-dap contributors.

https://github.com/llvm/llvm-project/pull/162952